RU1792642C - Device for measuring volume of gas flow - Google Patents

Abstract

The invention relates to medical equipment, in particular to devices for measuring the exhaled air volume of marine animals. The purpose of the invention is to increase the measurement accuracy by eliminating the influence of the inertia of the impeller in determining the start and end of the measurement, as well as to increase the reliability of operation while simplifying the device. The device for measuring the volume of an intermittent gas stream contains a flow housing, in the channel of which there is an impeller connected to an optical system including a photosensor connected to a pulse shaper, a pulse counter, a gas flow volume measuring time allocation unit, and an information output unit. What is new in the device is the implementation of a gas flow volume burden separation unit comprising a time discriminator, reset and write pulse shapers, a clock counter, a clock generator, a comparison circuit and a delay circuit. The use of infrared radiation sources with photodetectors in the photosensor, which provide noise immunity of the measurement, is also new. 1 s.p. f-ly, 3 ill. k

Description

The invention relates to devices for measuring the volume of an intermittent gas flow, in particular to devices for measuring the expiratory air volume of marine animals under real conditions.

The aim of the invention is to increase the accuracy of measurements by eliminating the influence on the inertia of the impeller, as well as increasing the noise immunity.

In FIG. 1 shows a block diagram of a device; in FIG. 2 is a graph of gas volumetric flow: FIG. 3 is a graph of a sensor impeller rotation speed.

The device for measuring the volume of the gas flow is a sensor 1 (primary converter) in the form of a flow housing, in the channel of which there is an impeller 2 connected to an optical system including infrared radiation sources 3 and photodetectors 4 connected to a pulse former 5, a pulse counter 6, a time allocation unit for measuring the volume of the gas stream 7 and the recorder.

The gas flow volume measuring time allocation unit comprises a time discriminator 9, the input of which is connected to |

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it with the output of the pulse shaper. 5, and the output with the input of the pulse counter 6. The output of the pulse counter 6 is connected to the inputs of the pulse shaper write 10 and the pulse shaper reset 11, the outputs of which are connected to the clock counter 12 associated with the output of the clock thirteen.

The output of the write pulse generator 10 is connected to the inputs of the comparison circuit 14 and the delay circuit 15, the second and third inputs of which are respectively connected to the outputs of the comparison circuit 14 and the clock generator 13, the output of which is connected to the input of the comparison circuit 14. The outputs of the clock counter 12 are connected to the inputs of the comparison circuit 14, and the outputs of the delay circuit 15 are connected respectively to the inputs of the recorder 8 and the reset pulse shaper 11.

Other inputs of the recorder 8 are connected to the output of the temporary discriminator 9 and the outputs of the pulse counter 6, while one of the inputs of the Resolution counter of the pulse counter 6 is connected to the output of the recorder 8.

The device operates as follows ...

The gas flow passing through the housing of the sensor 1 rotates the impeller 2, which, when rotated, modulates the radiation incident on the two photodetectors 4. The change in the radiation flux is converted into a measured signal by the phase detector of the pulse shaper 5, which forms a sequence of pulses and determines the direction impeller rotation and. accordingly, the direction of gas flow. From pulse former 5, the signal is fed to a time discriminator 9, which determines the origin of the signals (th value). In this case, the discriminator 9 transmits to the pulse counter b only those signals whose repetition period is less than a predetermined value, which eliminates the possibility of errors from accidental movement of the impeller, i.e. ft UN

The state O of the pulse counter 6 sets the entire system to its original state. The first signal supplied to the pulse counter corresponds to the origin (time 1n).

After one revolution of the impeller, the signal from pulse counter 6, which is a multiple of the number of modulation holes of the impeller, is fed to the input of the pulse shaper 10 and the pulse shaper 11 (time ti ... tk).

A write pulse from the driver 10 writes the state of the clock counter 12 to the comparison circuit 14. At the same time, the same pulse sets the delay circuit 15 to the zero position. As a delay circuit, a clock counter was used, the corresponding states of which are output to the driver 11 and the recorder 8.

A write pulse from the driver 10 writes the state of the clock counter 12 to the comparison circuit 14. At the same time, the same pulse sets the delay circuit 15 to the zero position. After the end of the recording pulse, signals are generated by the shaper by a reset pulse 11.

The signals exiting from the reset pulse generator 11 set the clock counter 12 to the zero position, after which a signal is issued enabling the counting of clock pulses received from. clock generator 13.

Thus, the counter of clock pulses 12 registers the time intervals between tH and c; ti and t2; t2 and ta etc. ,

If the impeller rotation time is equal to or greater than the previous revolution time

(tn + 1 - tn Stn + 2 - tn-i), Comparison Scheme 14

gives a signal to the input of the delay circuit 15,

resolving count of clock pulses from

generator 13. After that, through a given:

the time determined by the requirement for the reliability of the measurement, which is influenced by the pulsation of the gas stream, the delay circuit 15 gives a inhibit signal to the reset pulse shaper 11 (tm-tm;

tm + 2 - tm + 1 Cumin). AFTER 6 WHICH The generation of reset pulses is stopped and the counting of clock pulses by the counter 12 is prohibited, i.e. the minimum time of one revolution of the impeller (Cmin) is stored. In the process of passing gas sweat.

they compare the time of subsequent rotations of the impeller with respect to Tmin. When the value of T t tk - tR + t exceeds Tmin by a predetermined value, the signal from the delay circuit is supplied to the recorder 8, which first captures the value of the counter 6 (end of measurement Tk}, then outputs the measurement result to external devices, for example, recording, integrating, A computer and others, after which it sets the pulse counter b to zero and the circuit is set to its original state.

Consequently, counter 6 registers impulses from the impeller 2 only during the measurement of Tism tk - tH.

Before starting the next measurement, the device blocks are reset as follows: after setting counter 6 to the zero position, the signal removes the blocking of the reset pulse generator 11 and counter 12. The signal from the write pulse generator 10 sets delay circuit 15 to zero position. When the impeller is braked, the pulse frequency from the former 5 will become less than the set value (co (He), the time discriminator 9 does not pass signals to the counter 6 and at the same time gives a signal to the recorder 8, the response signal from which unlocks the counter 6.

The device is ready for the next measurement.

The device is used to measure the exhaled air volume of marine animals in apparatus for physiological monitoring of biological objects. The design of the sensor is easy to manufacture and reliable in operation.

The use of an infrared radiation source with photodetectors in the device’s photosensor can improve the accuracy of measuring the volume of an intermittent gas stream by reducing the influence of the aquatic environment on the photo-measuring channel, as well as by measuring the output volume of mammals, both on the surface and under water.

Claims (2)

SUMMARY OF THE INVENTION 1. A device for measuring the volume of a gas stream, comprising a flow-through housing of a sensor, in the channel of which there is an impeller with an optical system including a photosensor connected to a pulse former, a pulse counter. time allocation unit and recorder. It is noteworthy that, in order to increase the measurement accuracy by eliminating the influence of the impeller inertia on the result, the time allocation unit includes a time discriminator, the input of which is connected to the output of the pulse generator and pulse counter input. and the output - with the first input of the cut-out of the pulse counter and the first input of the recorder, the second input and output of which are connected respectively by the outputs and the second input of the resolution of the pulse counter, series-connected pulse generator recording, the comparison circuit and the delay circuit, the first output which is connected to the recorder enable input, the zero input is to the output of the recording pulse generator, as well as a series-connected clock generator, the output of which is also connected to the second input of the delay circuit and the second input of the comparison circuit, and a clock counter, the output of which is connected to the third the input of the comparison circuit, the installation input is zero and the enable input is with the corresponding outputs of the reset pulse generator, the first input of which is connected to the second output of the pulse counter and to an ode to the recording pulse generator, and the second input to the second output of the delay circuit. 2. The device according to claim 1, with the proviso that, in order to increase noise immunity, the photosensor includes an infrared radiation source with photodetectors connected to a pulse shaper including a phase detector. Editor Fig.} Compiled by N. Phil kin Techred M. Morgenthal Proofreader S. Baker